New smartphones will be able to see what the naked eye cannot. Virus and nanoparticle-based DNA sensors will be able to detect and analyze organisms one-thousandth of the width of a human hair.Dr. Ozcan previously
modded a cellphone into a portable blood tester capable of monitoring HIV, malaria, leukemia and detecting diseases.

The development of DNA biosensors is of increasing importance due to the growing demand for rapid and reliable methods for GMO detection.

"Modern biological research is also allowing an extension of laboratory devices on to small computer chips to detect biological information within DNA sequences," said biotech specialist Dr. Marek Banaszewski. "Bioinformatic algorithms within programs will aid the identification of transgenes, promoters, and other functional elements of DNA, making detection of genetically modified foods on-the-spot and real-time without transportation to a laboratory."

Aydogan Ozcan, a professor of electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, and his team have created a portable smartphone attachment that can be used to perform sophisticated field testing to detect viruses and bacteria without the need for bulky and expensive microscopes and lab equipment. The device weighs less than half a pound.

“This cellphone-based imaging platform could be used for specific and sensitive detection of sub-wavelength objects, including bacteria and viruses and therefore could enable the practice of nanotechnology and biomedical testing in field settings and even in remote and resource-limited environments,” Ozcan said. “These results also constitute the first time that single nanoparticles and viruses have been detected using a cellphone-based, field-portable imaging system.”

Your smartphone now can see what the naked eye cannot: A single virus and bits of material less than one-thousandth of the width of a human hair.

Aydogan Ozcan, a professor of electrical engineering and bioengineering at the UCLA Henry Samueli School of Engineering and Applied Science, and his team have created a portable smartphone attachment that can be used to perform sophisticated field testing to detect viruses and bacteria without the need for bulky and expensive microscopes and lab equipment. The device weighs less than half a pound.
This cellphone-based imaging platform could be used for specific and sensitive detection of sub-wavelength objects, including bacteria and viruses and therefore could enable the practice of nanotechnology and biomedical testing in field settings and even in remote and resource-limited environments,” Ozcan said. “These results also constitute the first time that single nanoparticles and viruses have been detected using a cellphone-based, field-portable imaging system.”

Capturing clear images of objects as tiny as a single virus or a nanoparticle is difficult because the optical signal strength and contrast are very low for objects that are smaller than the wavelength of light.

Brian Cunningham, a professor of electrical and computer engineering and of bioengineering at Illinois, is also devising technology for biodetection.“We’re interested in biodetection that needs to be performed outside of the laboratory,” he stated. “Smartphones are making a big impact on our society -- the way we get our information, the way we communicate. And they have really powerful computing capability and imaging. A lot of medical conditions might be monitored very inexpensively and non-invasively using mobile platforms like phones. They can detect molecular things, like pathogens, disease biomarkers or DNA, things that are currently only done in big diagnostic labs with lots of expense and large volumes of blood.”

The wedge-shaped cradle created by Cunningham's team contains a series of optical components -- lenses and filters -- found in much larger and more expensive laboratory devices. The cradle holds the phone’s camera in alignment with the optical components.

At the heart of the biosensor is a photonic crystal. A photonic crystal is like a mirror that only reflects one wavelength of light while the rest of the spectrum passes through. When anything biological attaches to the photonic crystal -- such as protein, cells, pathogens or DNA -- the reflected color will shift from a shorter wavelength to a longer wavelength.

In addition, Cunningham’s team is working on biosensing tests that could be performed in the field to detect toxins in harvested corn and soybeans, and to detect pathogens in food and water.

In the ACS Nano paper, Ozcan details a fluorescent microscope device fabricated by a 3-D printer that contains a color filter, an external lens and a laser diode. The diode illuminates fluid or solid samples at a steep angle of roughly 75 degrees. This oblique illumination avoids detection of scattered light that would otherwise interfere with the intended fluorescent image.

Using this device, which attaches directly to the camera module on a smartphone, Ozcan’s team was able to detect single human cytomegalovirus (HCMV) particles. HCMV is a common virus that can cause birth defects such as deafness and brain damage and can hasten the death of adults who have received organ implants, who are infected with the HIV virus or whose immune systems otherwise have been weakened. A single HCMV particle measures about 150-300 nanometers; a human hair is roughly 100,000 nanometers thick.

In a separate experiment, Ozcan’s team also detected nanoparticles -- specially marked fluorescent beads made of polystyrene -- as small as 90-100 nanometers.

To verify these results, researchers in Ozcan’s lab used other imaging devices, including a scanning electron microscope and a photon-counting confocal microscope. These experiments confirmed the findings made using the new cellphone-based imaging device.

For more information on the Ozcan Research Group, visit http://org.ee.ucla.edu Ozcan is a founder of the mobile microanalysis startup company Holomic LLC, which seeks to commercialize imaging and sensing technologies licensed from the UCLA Office of Intellectual Property and Industry Sponsored Research.

Other handheld devices currently in development are portable chemiluminescence detectors, but based on enzyme-catalyzed reactions emitting light. The detection devices for nucleic acids, biotin associated with the target DNA provides the handle for the chemiluminescent detection. The non-radioactive DNA detection chemistry will be able to readily identify single-copy genes in transgenic plants making them suitable for GMO detection.

Marco Torres is a research specialist, writer and consumer advocate for healthy lifestyles. He holds degrees in Public Health and Environmental Science and is a professional speaker on topics such as disease prevention, environmental toxins and health policy.